function init_modules() {
    initCompute()
}
var initCompute = (
    function() {
        var oDiv = document.getElementsByTagName("div")[0]

        function init() {
            bindEvent()
        }

        function bindEvent() {

            oDiv.addEventListener('click', btnClick)
        }

        function btnClick(e) {
            var e = e || window.event,
                tar = e.target || e.srcElenment,
                tagName = tar.tagName.toLowerCase(),
                first = Number(document.getElementById('first').value),
                second = Number(document.getElementById('second').value)
            if (tagName === 'button') {
                var field = tar.getAttribute('data-field');
                console.log(first);
                switch (field) {
                    case 'plus':
                        console.log(utils.plus(first, second));
                        break
                    case 'minus':
                        console.log(utils.minus(first, second));
                        break
                    case 'mul':
                        console.log(utils.mul(first, second));
                        break
                    case 'div':
                        console.log(utils.div(first, second));
                        break
                    default:

                }
            }
        }
        return function() {
            init()
        }
    }
)()